“We see SMRs as having enhanced safety and security attributes; the safety largely due to the lower power levels and the greater ability to rely on passive heat-removal systems. Certainly we expect them to come in at a lower cost which makes them more affordable and more feasible for a large number of utilities. Shorter construction schedules are also a potential benefit due to modular construction. Factory fabrication also offers the capability to improve the quality of the product and replicate it in factory setting. And as electric demand increased incrementally, we expect the SMRs to be able to fill that market. The market space is great, both domestically and internationally. We see a large need over the next several decades to replace fossil-fuel plants, and these small reactors have an opportunity to either replace or repower as we retire those units."
– John Kelly, Deputy Assistant Secretary, Nuclear Reactor Technologies, Department of Energy, Office of Nuclear Energy, addressing the U.S. Nuclear Regulatory Commission, Briefing on Small Modular Reactors in March 2011, Transcript – page 5
Cutaway of a Westinghouse 225 MWe SMR
Nuclear power plants have been generating reliable base-load electricity with low greenhouse gas emissions since the 1950s. Historically nuclear power plants have been built larger and larger. This was to obtain economies of scale in deployment to overcome the high fixed construction costs. As a consequence, modern nuclear power plants incurred substantial financing costs and required large, well connected electricity grids.
Currently there are 433 power reactors operating in 31 countries supplying ~14% of the world’s total electricity demand. Modern power reactors typically have an output of >1,000MW electrical which is too large for small countries or small grid systems.
The International Atomic Energy Agency (IAEA) defines “small" as less than 300 MWe but many SMRs have outputs in the range 25-100 MWe.
A market is developing for smaller reactors – in particular for SMRs, which can supply low-emissions, high capacity factor, and reliable power in remote locations or for small grid systems. They represent a new stage in nuclear reactor design and have the capacity to provide an economically competitive method of electrical power generation.
There is extensive experience of much of the technology employed by SMRs. For many years they have been the power supply for submarines and icebreakers, where totally reliable power with long periods between refuelling is essential.
Depending on the technology, many SMR designs can incorporate the following features:
Copyright © 2017 SMR Nuclear Technology. All Rights Reserved.